弥散张量成像对早期肌萎缩侧索硬化症上运动神经元损害的诊断意义

The Diagnostic Value of Diffusion Tensor Imaging in Identifying Upper Motor Neuron Damage of Amyotrophic Lateral Sclerosis

目的:探讨弥散张量成像(DTI)在发现早期肌萎缩侧索硬化症(ALS)上运动神经元损害中的临床意义。方法:21例ALS患者在行DTI检查时,8例无明显上运动神经元(UMN)受累体征,但在病程后期均出现了临床锥体束征的ALS患者作为A组,13例有明确UMN损害体征的ALS患者作为B组,20例健康人作为对照组。对所有研究对象行轴位DTI扫描,选取感兴趣区(ROI)测量部分各向异性分数(FA)和平均弥散系数(MD)。结果:与对照组比较,A组内囊后肢(u=3.974,P<0.01)、大脑脚(u=3.580,P<0.01)、延髓锥体(u=2.402,P<0.05)处的FA值明显减低,内囊后肢(u=2.168,P<0.05)处的MD值增高,A、B2组间该3个ROI处的FA、MD值差异无统计学意义。结论:DTI可发现ALS早期UMN损害,有助于ALS的早期诊断。

Objective： To explore the clinical value of diffusion tensor imaging （DTI） in finding early damage of upper motor neuron （UMN） in patients with amyotrophic lateral sclerosis （AKS）. Methods：Eight patients in group A had no sign of UMN damage when doing DTI examination, but all developed clinical pyramidal signs. Group B included thirteen patients who had definite sign of UMN damage. Twenty healthy volunteers served as control group. All subjects underwent a DTI se- quence. The fractional anisotropy （FA） and mean diffusivity （MD） were measured from the chosen region of interest （ROI）. Results：In group A, FA decreased on the posterior limb of internal capsule（PIC）（u=3.974, P 〈 0.01 ）, cerebral peduncle （u= 3.580, P 〈 0.01 ）and the pyramids of medulla oblongata （u=2.402, P 〈 0.05 ）, MD increased on the PIC level （u=2.168, P 〈 0.05 ）, compared with those in the control group. There were no statistical differences in FA and MD on those three ROIs be- tween group A and B. Conclusion： DTI can detect early damage of UMN of ALS patients, which would facilitate potential earlier diagnosis of ALS.